From 1965 until the end of 1966 the U.S. Space Agency NASA tested the technology and processes required in Space for a manned Lunar landing and return to Earth. During this period they launched ten manned and two unmanned missions using the "Gemini" space craft. In addition to controlled re-entry, the first changes in position and orbit, long-duration flights, docking manoeuvres and "Space Walk" missions were undertaken. A modified two-stage Titan II launch vehicle from the U.S. Air Force was used to launch of the 3.5-ton spacecraft. In the case of an aborted launch or an accident during landing, the astronauts were able to catapult themselves out of the capsule using their ejection seats. The Astronaut's protective suit consisted of 23 layers of fabric and weighed 13 kilograms. Out of a pool of 30 NASA astronauts, the experienced aviator Virgil I"Gus" Grissom was chosen to be "Mission Commander" and John W. Young to be the pilot of the first manned flight of the "Gemini" program. After a four-hour flight on 23 March 1965 the capsule "Molly Brown" from "Gemini 3" landed safely in the Atlantic Ocean.